It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Wednesday, August 06, 2025
PATRIARCHY PROJECTS BODY IMAGE
Adolescent girls who have weight concerns despite not being obese are more likely to also experience depression and suicidality
Adolescent girls who have weight concerns despite not being obese are more likely to also experience depression and suicidality, per Korean survey of more than 50,000 middle and high school students
Examples of Fe-rich and silica-rich impact microspherules (a and b) and metallic dust particles (MDPs; c and d) interpreted as cometary dust from Baffin Bay cores. Yellow arrows show particles of FeSi, FeS, and FeCr on microspherules (a and b) and NiFe, low-O2 Fe, and native Fe on metallic particles (c and d). Note folded edges of MDP in panel d.
Credit: Moore et al., 2025, PLOS One, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)
Analysis of ocean sediments has surfaced geochemical clues in line with the possibility that an encounter with a disintegrating comet 12,800 years ago in the Northern Hemisphere triggered rapid cooling of Earth’s air and ocean. Christopher Moore of the University of South Carolina, U.S., and colleagues present these findings in the open-access journal PLOS One on August 6, 2025.
During the abrupt cool-off—the Younger Dryas event—temperatures dropped about 10 degrees Celsius in a year or less, with cooler temperatures lasting about 1,200 years. Many researchers believe that no comet was involved, and that glacial meltwater caused freshening of the Atlantic Ocean, significantly weakening currents that transport warm, tropical water northward. In contrast, the Younger Dryas Impact Hypothesis posits that Earth passed through debris from a disintegrating comet, with numerous impacts and shockwaves destabilizing ice sheets and causing massive meltwater flooding that shut down key ocean currents.
However, the impact hypothesis has been less well supported, lacking any evidence from ocean sediments. To address that gap, Moore and colleagues analyzed the geochemistry of four seafloor cores from Baffin Bay, near Greenland. Radiocarbon dating suggests the cores include sediments deposited when the Younger Dryas event began. To study them, the researchers used several techniques, including scanning electron microscopy, single-particle inductively coupled plasma time-of-flight mass spectrometry, energy dispersive spectroscopy, and laser ablation inductively coupled plasma mass spectrometry.
The analysis detected metallic debris whose geochemistry is consistent with comet dust. These occurred alongside microscopic spherical particles whose composition indicates a mostly terrestrial origin, with some materials believed to be extraterrestrial—suggesting these microspherules could have formed when comet fragments exploded just above or upon hitting the ground, melting materials together. The analysis also uncovered even smaller nanoparticles with high levels of platinum, iridium, nickel, and cobalt, which can be signs of extraterrestrial origin.
Together, these findings indicate a geochemical anomaly occurring around when the Younger Dryas event began. However, they do not provide direct evidence supporting the impact hypothesis. More research is needed to confirm whether the findings are indeed evidence of impact, and to firmly link an impact to climate cooling.
Dr. Christopher R. Moore adds: "Our identification of a Younger Dryas impact layer in deep marine sediments underscores the potential of oceanic records to broaden our understanding of this event and its climatological impacts."
Dr. Mohammed Baalousha adds: "It is great to implement our unique nano-analytical tools in a new area of study, namely the analysis of nanoparticles generated or transported to the Baffin Bay core site during the Younger Dryas. We are always happy to implement our tools to support our colleagues and explore new frontiers."
Dr. Vladimir Tselmovich adds: "Collisions of the Earth with comets led to catastrophes leading to climate change, to the death of civilizations. One of these events was a catastrophe that occurred about 12,800 years ago. Having studied in detail the microscopic traces of this disaster in Baffin Bay, we were able to find multiple traces of cometary matter, which was identified by the morphology and composition of the microparticles found. The amount of comet dust in the atmosphere was enough to cause a short-term “impact winter,” followed by a 1,400-year cooling period. The results obtained confirm the hypothesis that the Earth collided with a large comet about 12,800 years ago."
In your coverage, please use this URL to provide access to the freely available article in PLOS One: http://plos.io/4mfhOEH
Citation: Moore CR, Tselmovich VA, LeCompte MA, West A, Culver SJ, Mallinson DJ, et al. (2025) A 12,800-year-old layer with cometary dust, microspherules, and platinum anomaly recorded in multiple cores from Baffin Bay. PLoS One 20(8): e0328347. https://doi.org/10.1371/journal.pone.0328347
Author countries: U.S., Russian Federation, U.K., Czechia, Australia
Funding: This work made use of the University of Utah USTAR shared facilities supported, in part, by the MRSEC Program of the NSF under Award #DMR-1121252. G.K. appreciates the support from the Czech Science Foundation (Grant 23-06075S). We also thank the thousands of donors and members of the Comet Research Group (Grant 24-01) who have been crucial in making this research possible. In particular, we thank Eugene Jhong, who provided substantial gifts supporting this research to the University of South Carolina (C.R.M.) and the University of California, Santa Barbara (J.P.K). V.A.T.’s research was carried out within the framework of the Borok Geophysical Observatory, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, state task nos. FMWU-2022-0026. The funders had no role in study design, data collection and analysis, decision to publish, or the preparation of the manuscript.
A 12,800-year-old layer with cometary dust, microspherules, and platinum anomaly recorded in multiple cores from Baffin Bay
Article Publication Date
6-Aug-2025
COI Statement
The Comet Research Group (CRG), a 501(C) (3) nonprofit charitable organization, provided research funding. J.P.K., M.A.L., C.R.M., and A.W. volunteer their time as co-founders and directors of CRG. No co-author receives a salary, compensation, stock, or any other financial benefit from CRG, except for tax deductions for CRG donations by co-authors A.W., M.A.L., and T.W. All co-authors may receive reimbursements from their respective organizations for attending symposia on the research presented in this paper. A.W. is a co-author of a book related to the YDIH; he donates all proceeds to the non-profit Comet Research Group. The authors declare no other competing interests. This does not alter our adherence to PLOS ONE policies on sharing data and materials.
Waiting in line: Why six feet of social distancing may not be enough
Study, led by undergraduate physics majors at UMass Amherst and researchers at University of Cadiz, sharpens our understanding of how airborne-communicable diseases travel
AMHERST, Mass. – We all remember the advice frequently repeated during the COVID pandemic: maintain six feet of distance from every other human when waiting in a line to avoid transmitting the virus. While reasonable, the advice did not take into account the complicated fluid dynamics governing how the airborne particles actually travel through the air if people are also walking and stopping. Now, a team of researchers led by two undergraduate physics majors at the University of Massachusetts Amherst has modeled how aerosol plumes spread when people are waiting and walking in a line.
The results, published recently in Science Advances, grew out of a question that many of us may have asked ourselves when standing in marked locations six-feet apart while waiting for a vaccine, to pay for groceries or to get a cup of coffee: what’s the science behind six-feet of separation? If you are a physicist, you might even have asked yourself, “what is happening physically to the aerosol plumes we’re all breathing out while waiting in a line, and is the six-foot guideline the best way to design a queue?”
To find answers to these questions, two talented UMass Amherst undergrads, Ruixi Lou and Milo Van Mooy, took the lead.
“We wanted to know how the aerosols we breathe out are transported, but it turns out this is very difficult to do in a real waiting line,” says Lou, who is now a graduate student at the University of Chicago.
The ideal situation would be to have real humans standing in a real, moving line to test how their exhalations travel—a far-too risky proposition. Instead, Lou and Van Mooy decided to 3D-print a set of cylinders and human-shaped models and put them on a conveyor belt to see how the plumes moved. Their models “exhaled” colored dyes mimicking sneezes, coughs and regular breathing. They also ran computer simulations in collaboration with the group of Rodolfo Ostilla at the University of Cadiz, in Spain.
“What we found was really surprising,” says Van Mooy.
Since warm air rises, there is a slight updraft surrounding our bodies—and so the team expected to see the aerosol plumes rising. But instead, they observed a “downwash” effect, where the simple act of walking and waiting in a line caused the plumes to sink. Even more surprising was that, if the ambient temperature is close to our body temperature, as would be the case in a non-air-conditioned room in summer, those aerosols could be pushed toward the floor due to air currents. However, in a climate-controlled room, the difference in temperature between what we exhale and the ambient conditions are enough to drive those plumes aloft. If the temperature is in an intermediate range, it is quite possible that the aerosols can hover at just the right height for the next person in the line to inhale them as the line moves forward.
“Ultimately, there are no hard-and-fast rules about social distancing that will keep us safe or unsafe,” says senior author Varghese Mathai, assistant professor of physics at UMass Amherst. “The fluid dynamics of air are marvelously complex and general intuition often misleads, even for something as simple as standing in a line. We need to take space and time into account as we come up with our public health guidelines.”
The study authors created 3D printed models of humans, complete with windpipes, that could sneeze, cough and exhale.
Credit: Photo by Margie Christianson for Virginia Tech.
Dogs drink water wherever they happen to find it — a puddle, a pond, a toilet. But the stuff in their actual water bowls almost always comes from the same tap their owners use. When that water is contaminated, both dogs and humans may suffer.
The risk is especially high for the 15 million American households that rely on private wells, according to a new Virginia Tech study in the journal PLOS Water. In dog drinking water sampled from wells across the country, 64 percent contained excessive levels of at least one potentially toxic heavy metal, such as lead, iron, sulfur, or arsenic.
Whatever’s in the water is likely in your dog too.
That’s the conclusion reached by the transdisciplinary trio of faculty members who collaborated on the study:
Audrey Ruple, the Metcalf Professor of Veterinary Informatics
Marc Edwards, University Distinguished Professor and professor of civil and environmental engineering
Leigh-Anne Krometis, professor of biological systems engineering and Turner Faculty Fellow
“Dogs have historically been sentinels for heavy metal contamination in prior drinking water crises,” said Edwards, who cited not only the Flint, Michigan, water crisis that he’s well known for investigating, but also instances in Vermont and Massachusetts when a dog’s illness presaged lead poisoning in the pet’s human owners.
Sharing the same environment as their owners makes dogs a kind of “canary in the coal mine.” Their smaller sizes and shorter lifespans mean environmental toxins often affect dogs before they affect humans.
What’s different, Ruple said, is “they’re not sacrificial sentinels. With our dogs, we care deeply about the way that the environment is impacting their life, their health, and their longevity. And we can do something about it.”
Private wells pose hidden risks
As a member of the executive leadership team of the longitudinal Dog Aging Project, a multi-institutional project, Ruple has access to over 50,000 dogs that registered to participate. For this study, she invited a small selection of dog owners with wells to mail in samples of the water their dogs drink.
Why focus on well water? Municipal water must be tested regularly and meet federal standards, but private wells fly under the regulatory radar. In Virginia, 40 percent of well owners have no water treatment system at all, according to recent research by Krometis. “It's a big unknown risk sitting in your house,” she said.
Because heavy metal contaminants are often tasteless, odorless, and invisible, homeowners may not know there’s something in the water — until their dog gets sick. “Dogs living in these homes may be our first warning signs of environmental exposures in underserved rural areas,” Ruple said.
Water treatment systems make a difference
By comparing the results of water testing with existing data on the dogs’ health conditions, researchers identified some indicators that heavy metals may already be making dogs sick.
For instance, dogs whose drinking water was treated only with a sediment filter were more likely to have a diagnosed health problem, while dogs drinking well water treated by reverse osmosis were the least likely to be in poor health.
Future research will need to validate that correlation, but it’s already clear that wells using some health-based treatment systems can reduce heavy metals.
Protecting dogs helps protect people
Researchers urged households with well water to test and treat it. The Virginia Household Water Quality Program sponsored by Virginia Cooperative Extension offers free water testing throughout Virginia. “Knowledge is power and peace of mind,” said Krometis.
Dog owners are often quick to act when their pets’ health is at risk. When researchers told some study participants that their pet’s water showed elevated levels of arsenic, they immediately acted to mitigate the risk by treating their water.
“We care what happens to our dogs,” Ruple said. “We try to fix the environment for them too, not just for us. It highlights the strength of the relationship that we have with them. And I'm not just saying this because I am a dog person.”
Journal
PLOS Water
Article Publication Date
6-Aug-2025
What’s in your pup’s bowl? Heavy metals, reveals 10-state survey
A survey of pets who drink well water reports higher-than-advised levels of arsenic, lead and copper.
Companion dogs act as important sentinels of human health and wellbeing in considering a variety of risks and exposures, including potential illness from contaminated drinking water.
Credit: Sexton et al., 2025, PLOS Water, CC-BY 4.0 (https://creativecommons.org/licenses/by/4.0/)
Two-thirds of dogs tested in a recent survey consume higher-than-recommended levels of heavy metals in their drinking water, according to a study published August 6, 2025 in the open-access journal PLOS Water by Audrey Ruple from Virginia Tech, U.S., and colleagues. The survey, which focused on well water households in 10 states, uncovered 13 instances where arsenic, lead and copper tested above EPA-recommended levels.
Roughly 15 million U.S. households use private well water and are not protected by the EPA’s Safe Drinking Water Act, which regulates safety testing in drinking water. These households — and the canine companions inside — are at an increased risk for consuming heavy metals that leach into groundwater.
In this study, the researchers analyzed drinking water samples from 178 dogs in homes not served by municipal water sources. All dogs are part of the Dog Aging Project, a long-term study of canine health and aging. Samples ranged across 10 states and tested for 28 heavy metals, about half of which are regulated by the EPA. Owners mailed drinking water samples to the researchers and completed detailed surveys about their dogs’ health and the home’s drinking water supply.
Across all 178 samples obtained, the researchers found detectable levels of all 28 metals tested. Two-thirds of the samples tested included at least one heavy metal over the EPA’s maximum contaminant level (MCL) or health guidance levels. In 13 instances, arsenic, lead and copper tested above the EPA’s MCL guidance levels.
Correlations identified within the experiment include: nearby fracking sites are associated with more sodium and sulfur in the drinking water; railroad tracks are associated with increased levels of manganese; and dogs drinking from water treated with reverse osmosis or a sediment filter were less likely to have a non-chronic health condition.
The researchers emphasize that big-picture conclusions require further study, and expressed a desire to continue testing dogs’ drinking water composition juxtaposed to their long-term health. Ultimately, this information can help guide veterinary care decisions and improve the health of the dogs’ human companions.
The authors add: “Many households served by private wells are flying under the regulatory radar. Dogs living in these homes may be our first warning signs of environmental exposures in underserved rural areas.”
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In your coverage please use this URL to provide access to the freely available article in PLOS Water: https://plos.io/3ILgHyq
Citation: Sexton CL, O’Brien J, Lytle J, Rodgers S, Keyser A, Kauffman M, et al. (2025) Testing for heavy metals in drinking water collected from Dog Aging Project participants. PLOS Water 4(8): e0000296. https://doi.org/10.1371/journal.pwat.0000296
Author Countries: United States
Funding: This research is based on data collected by the Dog Aging Project, which is supported by U19 grant AG057377 from the National Institute on Aging (authors funded on this grant include: SR, AK, MK, MDD, and AR), a part of the National Institutes of Health. The publicly available data are housed on the Terra platform at the Broad Institute of MIT and Harvard. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
